Azo-pyeazotone dyes



United States Patent Ofltice 3,123,596 Patented Mar. 3,. 1964 3,123,596AZO-PYRAZGLONE DYES Robert W. Eltouhead, Reading, Pa., assignor toCrompton & Knowles Corporation, Worcester, Mass, a corporation ofMassachusetts No Drawing. Filed Feb. 5, 19.63, Ser. No. 256,266 7Claims. (Cl. 260-162) This invention relates to a new group of organiccompounds which are useful as dyes. The new compounds form the followingstructure:

SOsH I wherein y represents H or NO x represents H or --Cl.

It will also be understood that the compounds of this invention not onlyinclude the free acid but also the water soluble salts thereof.

The new compounds are obtained by diazotizing certain benzamido-benzenesulfonic acids and coupling the diazo to a phenyl methyl pyrazoloneunder alkaline conditions and thereafter recovering the dyestuffs.

The compounds prepared in accordance with the invention have unique andhighly valuable properties when used as dyes. They will dye polyurethanefibers and natural and synthetic polyarnide fibers such as nylons, silkand wool in pure lightfast yellow shades having a very high degree ofwashfastness even without after-treatments with fixatives. The dyeingcan be effected from neutral solution and with a very high degree of dyeexhaustion. Because of their neutral dyeing capability, the compounds ofthis invention can be used in mixed baths with direct dyes. Mixedfabrics, formed from cellulosic fiber and polyamide or polyurethane canbe dyed in a single bath. In addition, the yellow dyes produced inaccordance with this invention are characterized in that they exhibitmore of the greener shades of yellow, whereas most of the yellow dyesfor polyamide fiber now on the market tend more to the reddish.

Suitable benzamido-ben'zene sulfonic acids for use in accordance withthis invention include: 2 amino-4-p-nitro benzamido benzene sulfonicacid; 2 amino-4-benzamido benzene sulfonic acid; and 2 amino-4-m-nitrobenzamido benzene sulfonic acid. The corresponding ortho nitroderivative could also be employed but it is not commercially available.The intermediate compounds or bases as aforesaid can be prepared asfollows:

1 to 1.2 moles of the acid chloride (or the acid chloride dissolved in anon-reactive solvent such as 1,1,1 trichlorethane) is added over aperiod of 1-3 hours to a vigorously agitated solution of 1 mole of1,3-diaminobenzene-4-sulfonic acid which has been neutralized withsodium hydroxide to a pH of 7-8 and to which has been added 1.8 moles ofsodium acetate. After hours stirring the crude mono benzoyl derivativeis filtered off. It may be purified by recrystallization.

The bases prepared as described above can be diazotized and thereaftercoupled under alkaline conditions with pyrazolones such as1-phenyl-3-methyl-5-pyrazolone and 1-(2chlorphenyl)-3-methyl-5-pyrazolone, to give the dyes of the invention.

The following examples will serve to illustrate how the compounds ofthis invention can be prepared and used. In these examples, unlessotherwise indicated, parts are by weight; temperatures are given bydegrees centigrade and percentages are percentages by weight.

Example I 183, gm. of sodium nitrite dissolved in 3 mls. water wereadded to 4:4- gms. of 2 amino4-p-'nitro benzamido benzene sulfonic aciddissolved in mls. of water and 3 mls. of 20% sodium hydroxide solution.This solution was added to ice and water containing 8 mls. of 36%hydrochloric acid. After stirring 1 hour at 3 C., sulfamic acid wasadded to eliminate the excess nitrous acid. The resulting slurry of thediazo was added slowly to' a solution of 1.8 gm's. ofl-phen'yl-3-methyl-5=pyrazolone, dissolved in 70 mls. water plus 3 mls.of 20% sodium hydroxide solution. During coupling the pH was maintainedat 10 by the addition of 20% sodium hydroxide solution. After stirring 1hour 35 gms. of salt were added to the 700 ml. volume. An hour later thedyestuif was filtered off and dried. Obtained 5.3 gms. of productcontaining the sodium salt of- HO-G-III( 376 gms. of the potassium saltof 2 amino-4-p-nitro benzamido benzene sulfonic acid were pasted with 45mls. of 36% hydrochloric acid and 100 mls. water. After cooling. to 3 C.by the addition of ice, 7.73 gms. of sodium nitrite dissolved in 28 mls.of water were added.

After stirring for 2 /2 hours at 03 C. sulfamic acid was added toeliminate the excess nitrous acid; The resulting diazowas added over 10minutes to a filtered solution of 1- (2'chlorophenyl)-3-methyl-5-pyrazolone dissolved in 36 mls. of 20% sodiumhydroxide solution and 600 mls. water. During this time the pH was heldat 9.0 by the addition of 20% sodium hydroxide solution. After stirringovernight, the dystutf was filtered off and dried. Obtained 52.8 ofproduct containing the sodium salt of-- Example 111 49.5 gms. of 2amino-4-benzamido benzene sulfonic acid were ground and pasted with 67mls. 36% hydrochloric acid and mls. water. Ice was added to reduce thetemperature to 3 C. 10.5 gms. of sodium nitrite dissolved in 38 mls. ofwater were then added. After stirring 3 hours at 0-3 C., sulfamic acidwas added to eliminate the excess nitrous acid. The volume of diazoobtained was 930 mls. To a filtered solution of 14.4 gms. of1-phenyl-3-methyl-5-pyrazolone dissolved in 310 mls. water and 16.5 mls.of 20% sodium hydroxide solution, 465 mls. of the diazo slurry wereadded while stirring. During the 10 minute addition of diazo the pH wasmaintained at 9.5-10 by the addition of 20% sodium hydroxide solution.After stirring overnight the pH 'was 8.7. The dyestulf was filtered oiland dried. Ob-

tained 35.2 gins. of product containing the sodium salt 3 Example IV17.2 gms. of 1- (2' chlorophenyl)-3-methyl-5-pyrazolone were dissolvedin 370 mls. water and 27 mls. of 20% sodium hydroxide solution. Thesolution was filtered. With stirring, 465 mls. of the diazo slurryprepared as in Example III, were added over 10 minutes, the pH beingmaintained at 95-10 by the addition of 20% sodium hydroxide solution.After stirring overnight the pH was 8.7. The dyestufl? Was filtered offand dried Obtained 36.6 gms. of product containing the sodium salt of 27gms. of 2 amino-4-m-nitro benzamido benzene sulfonic acid were groundand pasted with 700 mls. Water and 40 mls. 36% hydrochloric acid. 6.4gms. sodium nitrite dissolved in 23 mls. Water were added. Afterstirring 2 /2 hours at -3 C. sulfamic acid was added to eliminate theexcess nitrous acid. The volume of diazo obtained Was 800 mls. 3.5 gms.of 1-phenyl-3-methyl-5- pyrazolone were dissolved in 300 mls. of Watercontaining 5 mls. of 20% sodium hydroxide solution. 200 mls. of thediazo were added over minutes, the pH being maintained at 10 by theaddition of sodium hydroxide solution. After stirring 2 hours at 20 C.gms. of salt Were added to the 500 mls. of coupling. Hydrochloric acid36% Was added to adjust the pH to 8.8. After stirring overnight thedyestulf Was filtered off and dried. Obtained 6.5 gms. of productcontaining the sodium salt of- In the above manner, 200 mls. of thediazo prepared as in Example V, were coupled to 4.2 gms. of 1-(2chlorophenyl)-3-methyl-5-pyrazolone dissolved in 300 mls. watercontaining 5 mls. of sodium hydroxide. Obtained 10.4 gms. of productcontaining the sodium salt of I claim: 1. A compound having thefollowing structure:

SOaH I wherein y represents a substituent selected from the groupconsisting of H and NO and Where x represents a substituent selectedfrom the group consisting of H and --Cl.

2. The water soluble salts of a compound according to claim 1.

3. The compound:

5. The compound:

7. The compound:

References Cited in the file of this patent FOREIGN PATENTS GreatBritain June 17, 1929 SOaH I

1. A COMPOUND HAVING THE FOLLOWING STRUCTURE: